1. Field of the Invention
The present invention relates to a processing system and more particularly to a chemical vapor deposition chamber useful for depositing dielectric materials on substrates during the fabrication of integrated circuits and other electronic devices.
2. Background of the Related Art
In the fabrication of integrated circuits and other electronic devices on substrates, multiple deposition and etch steps are performed in sequence to fabricate the desired electronic structures or devices. The trend has been to reduce the overall size of the features which make up the devices and to increase the density of devices formed on a single die. The goal in designing and fabricating these electronic devices is to achieve an overall increase in the speed and capacity of the overall device. This trend has caused a significant amount of research to be undertaken in the area of materials to accomplish these goals. As dimensions decrease, a need arises for materials with lower dielectric constants to act as insulators and less resistive materials to serve as conductors.
One area of research has been conducted in the area of dielectric materials which have a lower dielectric constant. These materials are useful in preventing interference and cross talk between adjacent metal layers, lines and other conducting features. As the trend continues, the goal is to reduce the overall thickness of the dielectric material disposed between conducting features with improved insulating properties. Examples of promising materials include porous oxides having at least some carbon content and insulative polymers or copolymers.
As new materials are investigated, new hardware is needed to perform the deposition steps on substrates. In addition, with the research continually developing, the hardware needs to be adaptable to accommodate a change in precursor gases as well as process conditions. Typically, processing hardware has been designed to accommodate a certain process and a change in process conditions required a change in hardware. For example, a chamber designed for the deposition of silicon dioxide, the traditional dielectric material used in semiconductor fabrication, has been configured to operate in the process regime required to deposit this material. A change in precursor materials or resultant film composition required a change in processing equipment as well as a change in the accompanying software. These required changes are costly and do not provide flexibility in integrating new processes.
Therefore, there is a need for a process system which can deposit new materials and which is adaptable to a change in process gas precursors and/or process conditions.